System and method for plasma plating

ABSTRACT

An exemplary system and method for plasma plating are provided to generate a deposition layer on a substrate. The method for plasma plating includes positioning a substrate within a vacuum chamber, positioning a depositant in a filament within the vacuum chamber, reducing the pressure in the vacuum chamber to a level at or below 4 milliTorr, and introducing a gas into the vacuum chamber at a rate to raise the pressure in the vacuum chamber to a level at or between 0.1 milliTorr and 4 milliTorr. In other embodiments, the gas is not required to be introduced. The method also includes applying a dc signal to the substrate at a voltage amplitude at or between 1 volt and 5000 volts, applying a radio frequency signal to the substrate at a power level at or between 1 watt and 50 watts, and heating the depositant to a temperature at or above the melting point of the depositant to generate a plasma in the vacuum chamber. The plasma will preferably include both positively charged gas and depositant ions that will be attracted to the substrate, which will be provided at a negative potential if the dc signal is provided at a negative polarity.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to the field of deposition technologyfor plating and coating materials and more particularly to a system andmethod for plasma plating.

BACKGROUND OF THE INVENTION

Various deposition technologies exist for plating and coating materials.These various technologies include, for example, vacuum deposition orphysical vapor deposition (“PVD”), chemical vapor deposition (“CVD”),sputtering, and ion plating. These deposition technologies suffer fromvarious disadvantages. These disadvantages may include, for example,poor deposition layer adhesion, high cost, generation of environmentallywasteful products that are expensive and cumbersome to dispose, damageto the substrate, elevated substrate temperatures, nonuniform depositionlayers, inefficient use of expensive depositants, and inconsistentapplication of deposition layers.

SUMMARY OF THE INVENTION

From the foregoing it may be appreciated that a need has arisen for asystem and method for plasma plating that generates a controllable andrepeatable deposition layer on a substrate. In accordance with thepresent invention, a system and method for plasma plating are providedthat substantially eliminate one or more of the disadvantages andproblems outlined above.

According to an aspect of the present invention, a method for plasmaplating is provided to generate a deposition layer on a substrate. Themethod for plasma plating includes positioning a substrate within avacuum chamber, positioning a depositant in a filament within the vacuumchamber, reducing the pressure in the vacuum chamber to a level at orbelow 4 milliTorr, and introducing a gas into the vacuum chamber at arate to raise the pressure in the vacuum chamber to a level at orbetween 0.1 milliTorr and 4 milliTorr. In other embodiments, the gas isnot required to be introduced. The method also includes applying a dcsignal to the substrate at a voltage amplitude at or between 1 volt to5000 volts, applying a radio frequency signal to the substrate at apower level at or between 1 watt and 50 watts, and heating thedepositant to a temperature at or above the melting point of thedepositant to generate a plasma in the vacuum chamber. The plasma willpreferably include both positively charged gas and depositant ions thatwill be attracted to the substrate, which will, preferably, be providedat a negative potential if the dc signal is provided at a negativepolarity.

According to another aspect of the present invention, a system forplasma plating is provided that generates a deposition layer on asubstrate. The system for plasma plating includes a vacuum chamber at apressure that extends from 0.1 milliTorr to 4 milliTorr, a filament withan associated depositant located on or in the filament, a platformpositioned within the vacuum chamber, a substrate positioned at or onthe platform, a dc power supply generating a dc signal at a voltage in arange that extends from 1 volt to 5000 volts, a radio frequencytransmitter generating a radio frequency signal at a power level definedby a range that extends from 1 watt to 50 watts, an electricallyconductive path that electrically couples the dc signal and the radiofrequency signal to the substrate, and a filament power controlelectrically coupled to the filament and generating a current throughthe filament at an amplitude to generate heat in the filament to meltthe depositant.

The present invention provides a profusion of technical advantages thatinclude the capability to controllably, repeatably, and reliably plate asubstrate using plasma plating to develop a deposition layer with a highadherence to the substrate.

Another technical advantage of the present invention includes thecapability to control the thickness of the deposition layer to around500 Angstroms, while developing a more uniform deposition layerthickness that is repeatable from one application to the next.

Another technical advantage of the present invention includes thecapability to efficiently use depositants to minimize the consumption ofdepositants, which often are expensive precious metals such as gold andeven platinum. These efficiencies are achieved through the properplacement of filaments and the use of proper operational parameters.This significantly reduces overall costs.

Yet another technical advantage of the present invention includes thecapability to perform plasma plating without heating up the substrate toextreme temperatures that often damage the substrate through molecularand/or metallurgical changes. This ensures that a deposition layer canbe developed without the danger of possibly unknowingly damaging asubstrate. This is especially significant when the failure of asubstrate in its system or intended use results in a safety hazard. Thisalso provides the significant advantage of allowing the substrate to behandled and used immediately after the plasma plating process.

Still yet another technical advantage of the present invention includesthe capability to perform plasma plating without bombarding thesubstrate with high energy ions, like ion plating, which could damage oralter the substrate through molecular, metallurgical, and possiblychemical changes. This is because plasma plating is believed to beachieved at medium energy levels, such as at a medium energy level onthe average of between 10 eV and 90 eV, such that good adhesion isachieved but no metallurgical or chemical changes occur to the substratedue to the relatively shallow depth of imbedment of the depositionlayer.

Still yet another technical advantage includes the capability to plate asubstrate with a deposition layer with a thickness that is small enoughso as not to change the functional shape of the substrate, such as abolt, a nut, a fastener, and other components with strict tolerances.The present invention will also work in the presence of an oxidationlayer.

Yet another technical advantage includes the capability to plate asubstrate with a deposition layer without generating waste by productsor any environmentally hazardous waste. This is significant.

Other technical advantages are readily apparent to one skilled in theart from the following figures, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following briefdescription, taken in connection with the accompanying drawings anddetailed description, wherein like reference numerals represent likeparts, in which:

FIG. 1 is a schematic diagram that illustrates a system for plasmaplating that can be used to plate materials, according to an embodimentof the present invention;

FIG. 2 is a top view of a vacuum chamber of a system for plasma platingthat illustrates one embodiment of a platform implemented as aturntable;

FIG. 3 is a side view that illustrates the formation and dispersion of aplasma around a filament to plasma plate a substrate according to anembodiment of the present invention;

FIG. 4 is a sectional view that illustrates a deposition layer thatincludes a base layer, a transition layer, and a working layer;

FIG. 5 is a flowchart that illustrates a method for plasma platingaccording to an embodiment of the present invention; and

FIG. 6 is a flowchart that illustrates a method for backsputtering usingthe system of the present invention, according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood at the outset that although an exemplaryimplementation of the present invention is illustrated below, thepresent invention may be implemented using any number of techniques,whether currently known or in existence. The present invention should inno way be limited to the exemplary implementations, drawings, andtechniques illustrated below, including the exemplary design andimplementation illustrated and described herein.

FIG. 1 is a schematic diagram that illustrates a system 10 for plasmaplating that can be used to plate any of a variety of materials,according to an embodiment of the present invention. The system 10includes various equipment used to support the plasma plating of asubstrate 12 within a vacuum chamber 14. Once appropriate operatingparameters and conditions are achieved, a depositant provided in afilament 16 and a filament 18 may be evaporated or vaporized to form aplasma. The plasma will contain, generally, positively charged ions fromthe depositant and will be attracted to the substrate 12 where they willform a deposition layer. The plasma may be thought of as a cloud of ionsthat surround or are located near the substrate 12. The plasma willgenerally develop a dark region, near the closest surface of thesubstrate 12 from the filament 16 and the filament 18, that providesacceleration of the positive ions to the substrate 12.

The filament 16 and the filament 18 reside within the vacuum chamber 14along with a platform 20, which supports the substrate 12. A driveassembly 22 is shown coupled between a drive motor 24 and a main shaftof the platform 20 within the vacuum chamber 14. In the embodiment shownin FIG. 1, the platform 20 is provided as a turntable that rotateswithin the vacuum chamber 14. The drive assembly 22 mechanically linksthe rotational motion of the drive motor 24 with the main shaft of theplatform 20 to impart rotation to the platform 20. The rotation of themain shaft of the platform 20 is enhanced through various supportbearings such as a base plate bearing 28 and a platform bearing 30.

As is illustrated, the vacuum chamber 14 resides or is sealed on a baseplate 32. The vacuum chamber 14 may be provided using virtually anymaterial that provides the appropriate mechanical characteristics towithstand an internal vacuum and an external pressure, such asatmospheric pressure. For example, the vacuum chamber 14 may be providedas a metal chamber or as a glass bell. In an alternative embodiment, thebase plate 32 serves as the platform 20 to support the substrate 12. Thebase plate 32 may be thought of as part of the vacuum chamber 14.

The base plate 32 also provides mechanical support for the system 10while allowing various devices to feed through from its bottom surfaceto its top surface within the vacuum chamber 14. For example, thefilament 16 and the filament 18 receive power from a filament powercontrol module 34. It should be noted that although two filament powercontrol modules 34 are shown in FIG. 1, preferably, these two modulesare implemented as one module. In order to provide power to the filament16 and the filament 18, electrical leads must feed through the baseplate 32 as illustrated in FIG. 1. Similarly, the drive motor 24 mustalso penetrate or feed through the base plate 32 to provide mechanicalaction to the drive assembly 22 so that the platform 20 may be rotated.The electrical feed through 26, described more fully below, also feedsthrough the base plate 32 and provides an electrical conductive pathbetween the platform 20 and various signal generators, also describedmore fully below. In a preferred embodiment, the electrical feed through26 is provided as a commutator that contacts the bottom surface of theplatform 20, in the embodiment where the platform 20 is implemented as aturntable. The electrical feed through 26 may be implemented as acommutator and may be implemented as a metal brush which can contact thebottom surface of the platform 20 and maintain an electrical contacteven if the platform 20 rotates.

The filament power control module 34 provides an electric current to thefilament 16 and the filament 18. In one embodiment, the filament powercontrol module 34 can provide current to the filament 16 for aparticular duration, and then provide current to the filament 18 duringa second duration. Depending upon how the filaments are configured, thefilament power control module 34 may provide current to both thefilament 16 and the filament 18 at the same time or during separateintervals. This flexibility allows more than one particular depositantmaterial to be plasma plated onto the substrate 12 at different times.The filament power control module 34 preferably provides alternatingcurrent to the filaments, but may provide a current using any knownmethod of generating current. In a preferred embodiment, the filamentpower control module 34 provides current at an amplitude or magnitudethat is sufficient to generate enough heat in the filament 16 toevaporate or vaporize the depositant provided therein.

In order to ensure even heating of the depositant, which will beprovided at or in the filament 16 or the filament 18, the currentprovided by the filament control module 34 will preferably be providedusing incremental staging so that a more even heat distribution willoccur in the depositant that is being melted within the vacuum chamber14.

In a preferred embodiment, the platform 20 is implemented as a turntableand rotates using the mechanical linkage as described above. A speedcontrol module 36, as shown in FIG. 1, may be provided to control thespeed of the rotation of the platform 20. Preferably, the rotation ofthe platform 20 occurs at a rate from five revolutions per minutes to 30revolutions per minute. It is believed that an optimal rotational rateof the platform 20 for plasma plating is provided at a rotational rateof 12 revolutions per minute to 15 revolutions per minute. Theadvantages of rotating the platform 20 are that the substrate 12 can bemore evenly plated or coated. This is especially true when multiplesubstrates are provided on the surface of the platform 20. This allowseach one of the multiple substrates to be similarly positioned, onaverage, within the vacuum chamber 14 during the plasma plating process.

In other embodiments, the platform 20 may be provided at virtually anydesired angle or inclination. For example, the platform 20 may beprovided as a flat surface, a horizontal surface, a vertical surface, aninclined surface, a curved surface, a curvilinear surface, a helicalsurface, or as part of the vacuum chamber such as a support structureprovided within the vacuum chamber. As mentioned previously, theplatform 20 may be stationary or rotate. In an alternative embodiment,the platform 20 includes rollers that may be used to rotate one or moresubstrates.

The platform 20, in a preferred embodiment, provides or includes anelectrically conductive path to provide a path between the electricalfeed through 26 and the substrate 12. In one embodiment, platform 20 isprovided as a metal or electrically conductive material such that anelectrically conductive path is provided at any location on the platform20 between the electrical feed through 26 and the substrate 12. In suchas a case, an insulator 21, will be positioned between the platform 20and the shaft that rotates the platform 20 to provide electricalisolation. In another embodiment, the platform 20 includes electricallyconductive material at certain locations on its top surface thatelectrically coupled to certain locations on the bottom surface. In thismanner, the substrate 12 can be placed at an appropriate location on thetop side of the platform 20 while the electrical feed through 26 may bepositioned or placed at an appropriate location on the bottom side ofthe platform 20. In this manner, the substrate 12 is electricallycoupled to the electrical feed through 26.

The electrical feed through 26 provides a dc signal and a radiofrequency signal to the platform 20 and the substrate 12. The desiredoperational parameters associated with each of these signals aredescribed more fully below. Preferably, the dc signal is generated by adc power supply 66 at a negative voltage and the radio frequency signalis generated by an rf transmitter 64 at a desired power level. The twosignals are then preferably mixed at a dc/rf mixer 68 and provided tothe electrical feed through 26 through an rf balancing network 70, whichprovides signal balancing by minimizing the standing wave reflectedpower. The rf balancing network 70 is preferably controlled through amanual control.

In an alternative embodiment, the platform 20 is eliminated, includingall of the supporting hardware, structures, and equipment, such as, forexample, the drive motor 24, and the drive assembly 22. In such a casethe substrate 12 is electrically coupled to the electrical feed through26.

The remaining equipment and components of the system 10 of FIG. 1 areused to create, maintain, and control the desired vacuum conditionwithin the vacuum chamber 14. This is achieved through the use of avacuum system. The vacuum system includes a roughing pump 46 and aroughing valve 48 that is used to initially pull down the pressure inthe vacuum chamber 14. The vacuum system also includes a foreline pump40, a foreline valve 44, a diffusion pump 42, and a main valve 50. Theforeline valve 44 is opened so that the foreline pump 40 can began tofunction. After the diffusion pump 42 is warmed or heated to anappropriate level, the main valve 50 is opened, after the roughing pump46 has been shut in by closing the roughing valve 48. This allows thediffusion pump 42 to further reduce the pressure in the vacuum chamber14 below a desired level.

A gas 60, such as argon, may then be introduced into the vacuum chamber14 at a desired rate to raise the pressure in the vacuum chamber 14 to adesired pressure or to within a range of pressures. A gas control valvecontrols the rate of the flow of the gas 60 into the vacuum chamber 14through the base plate 32.

Once all of the operating parameters and conditions are established, aswill be described more fully below in connection with FIGS. 5 and 6according to the teachings of the present invention, plasma platingoccurs in system 10. The substrate 12 may be plasma plated with adeposited layer, which may include one or more layers such as a baselayer, a transitional layer, and a working layer, through the formationof a plasma within the vacuum chamber 14. The plasma will preferablyinclude positively charged depositant ions from the evaporated orvaporized depositant along with positively charged ions from the gas 60that has been introduced within the vacuum chamber 14. It is believed,that the presence of the gas ions, such as argon ions, within the plasmaand ultimately as part of the depositant layer, will not significantlyor substantially degrade the properties of the depositant layer. Theintroduction of the gas into the vacuum chamber 14 is also useful incontrolling the desired pressure within the vacuum chamber 14 so that aplasma may be generated according to the teachings of the presentinvention. In an alternative embodiment, the plasma plating process isachieved in a gasless environment such that the pressure within thevacuum chamber 14 is created and sufficiently maintained through avacuum system.

The generation of the plasma within the vacuum chamber 14 is believed tobe the result of various contributing factors such as thermionic effectfrom the heating of the depositant within the filaments, such as thefilament 16 and the filament 18, and the application of the dc signaland the radio frequency signal at desired voltage and power levels,respectively.

The vacuum system of the system 10 may include any of a variety ofvacuum systems such as a diffusion pump, a foreline pump, a roughingpump, a cryro pump, a turbo pump, and any other pump operable or capableof achieving pressures within the vacuum chamber 14 according to theteachings of the present invention.

As described above, the vacuum system includes the roughing pump 46 andthe diffusion pump 42, which is used with the foreline pump 40. Theroughing pump 46 couples to the vacuum chamber 14 through the roughingvalve 48. When the roughing valve 48 is open, the roughing pump 46 maybe used to initially reduce the pressure within the vacuum chamber 14.Once a desired lower pressure is achieved within the vacuum chamber 14,the roughing valve 48 is closed. The roughing pump 46 couples to thevacuum chamber 14 through a hole or opening through the base plate 32.The roughing pump 46 will preferably be provided as a mechanical pump.In a preferred embodiment of the vacuum system of the system 10 as shownin FIG. 1, the vacuum system in this embodiment also includes a forelinepump 40 coupled to a diffusion pump 42 through a foreline valve 44. Theforeline pump 40 may be implemented as a mechanical pump that is used incombination with the diffusion pump 42 to reduce the pressure within thevacuum chamber 14 to a level even lower than that which was producedthrough the use of the roughing pump 46.

After the roughing pump 46 has reduced the pressure within the vacuumchamber 14, the diffusion pump 42, which uses heaters and may requirethe use of cooling water or some other substance to cool the diffusionpump 42, couples with the vacuum chamber 14 through a main valve 50 andthrough various holes or openings through the base plate 32 as indicatedin FIG. 1 by the dashed lines above the main valve 50 and below theplatform 20. Once the diffusion pump 42 has been heated up and madeready for operation, the main valve 50 may be opened so that thepressure within the vacuum chamber 14 may be further reduced through theaction of the diffusion pump 42 in combination with the foreline pump44. For example, the pressure within the vacuum chamber 14 may bebrought below 4 milliTorr. During a backsputtering process, the pressurein the vacuum chamber 14 may be dropped to a level at or below 100milliTorr on down to 20 milliTorr. Preferably, the pressure within thevacuum chamber 14 during a backsputtering process will be at a level ator below 50 milliTorr on down to 30 milliTorr. During normal operationof the system 10 during a plasma plating process, the pressure withinthe vacuum chamber 14 may be reduced by the vacuum system to a level ator below 4 milliTorr on down to a value of 0.1 milliTorr. Preferably,the vacuum system will be used during a plasma plating process to reducethe pressure within the vacuum chamber 14 to a level at or below 1.5milliTorr on down to 0.5 milliTorr.

FIG. 2 is a top view of a vacuum chamber of a system for plasma platingthat illustrates one embodiment of a platform implemented as a turntable20. The turntable 20 is shown with substrates 12 a, 12 b, 12 c, and 12 dpositioned, symmetrically on the surface of the turntable 20. Theturntable 20 may rotate either clockwise or counterclockwise. Thesubstrates 12 a-12 d may be virtually any available material and areshown in FIG. 2 as round, cylindrical components such that the top viewof each of the substrates presents a circular form.

The filament power control module 34 is electrically coupled to a firstset of filaments 94 and 96 and a second set of filaments 90 and 92.Although the electrical connections are not fully illustrated in FIG. 2,it should be understood that the filament power control module 34 maysupply current to the first set of filaments 94 and 96 or to the secondset of filaments 90 and 92. In this manner, the deposition layer may beprovided with two sublayers such as a base layer and a working layer.The base layer will preferably be applied first through depositantsprovided in the first set of filaments 94 and 96 while the working layerwill be deposited on the base layer of the substrates 12 a-12 d usingthe depositants provided at the second set of filaments 90 and 92.

The arrangement of the substrates in FIG. 2 may be described as an arrayof substrates that include inwardly facing surfaces, which are closer tothe center of the turntable 20, and outwardly facing surfaces, which arecloser to the outer edge of the turntable 20. For example, the inwardlyfacing surfaces of the array of substrates 12 a-d will be presented tothe filament 92 and the filament 96, at different times of course, asthey are rotated near the filaments. Similarly, the outwardly facingsurfaces of the substrates 12 a-d will be presented to the filaments 90and 94 as they rotate near these filaments.

As mentioned previously, the filament power control module 34 mayprovide a current in virtually any form, such as a direct current or analternating current, but preferably provides current as an alternatingcurrent.

In operation, turntable 20 rotates, for example, in a clockwisedirection such that after substrate 12 b passes near or through thefilaments, the next substrate that will pass near or through thefilaments is substrate 12 c, and so on. In one example, the first set offilaments 94 and 96 are loaded with a depositant, such as nickel (ortitanium), and the second set of filaments are loaded with a depositantsuch as the metal alloy silver\palladium. This example illustrates a twoshot application or a two layer deposition layer.

After all of the operating parameters have been established within thevacuum chamber, as described throughout herein, the filament powercontrol module 34 may energize or provide alternating current to thefirst set of filaments 94 and 96 so that the nickel will evaporate orvaporize to form a plasma with the gas, such as argon gas, within thevacuum chamber. The positively charged nickel ions and the positivelycharged argon ions in the plasma will be attracted to the substrates 12a-d, which are at a negative potential. Generally, the closer thesubstrate is to the first set of filaments 90 and 92 as it rotates, themore material will be deposited. Because the turntable is rotating, auniform or more even layer will be applied to the various substrates.

After the first plasma has been plated onto the array of substrates 12a-d to form a base layer of the depositant layer on the substrates, thefilament power control module 34 is energized so that a sufficientamount of current is provided to the second set of filaments 90 and 92.Similarly, a plasma is formed between the argon ions and thesilver\palladium ions and the working layer is then formed to thesubstrates that are being rotated.

During the first shot when the base layer is being applied, theoutwardly facing surfaces of substrates 12 a-d are primarily coatedthrough the nickel depositant located in the filament 94. Similarly, theinwardly facing surfaces of the substrates are coated by the nickeldepositant located in the filament 96. The same relation holds true forthe second shot where the silver\palladium is plasma plated onto thesubstrates to form the deposit layer.

FIG. 3 is a side view that illustrates the formation and dispersion of aplasma around a filament 100 to plasma plate a substrate 12 according toan embodiment of the present invention. The filament 100 is implementedas a wire basket, such as tungsten wire basket, and is shown with adepositant 102 located within, and mechanically supported by thefilament 100. As the filament power control module 34 providessufficient current to the filament 100, the depositant 102 melts orvaporizes and a plasma 104 is formed. Of course, all of the operatingparameters of the present invention must be present in order to achievethe plasma state so that plasma plating may take place.

The substrate 12, which is provided at a negative potential, attractsthe positive ions of the plasma 104 to form a deposition layer. As isillustrated, the dispersion pattern of the plasma 104 results in most ofthe positive ions of the plasma 104 being attracted to the side adjacentor nearest to the filament 100 and the depositant 102. Some wrap aroundwill occur such as that illustrated by the plasma 104 contacting the topsurface of the substrate 12. Similarly, some of the positive ions of theplasma 104 may be attracted to the platform or turntable. As isillustrated, the present invention provides an efficient solution forthe creation of a deposition layer by ensuring that most of the ionsfrom the depositant are used in the formation of the deposition layer.

FIG. 4 is a sectional view that illustrates a deposition layer of thesubstrate 12 that includes a base layer 110, a transition layer 112, anda working layer 114. It should be noted at the outset that the thicknessof the various layers that form the deposition layer are grossly out ofproportion with the size of the substrate 12; however, the relativethicknesses of the various sublayers or layers of the deposition layerare proportionate to one another, according to one embodiment of thepresent invention.

Generally, the thickness of the entire deposition layer on thesubstrate, according to the teachings of the present invention, arebelieved to generally range between 500 and 20,000 Angstroms. In apreferred embodiment, the entire thickness of the deposition layer isbelieved to range between 3,000 and 10,000 Angstroms. The presentinvention provides excellent repeatability and controllability ofdeposition layer thicknesses, including all of the sublayers such as thebase layer 110, the transition layer 112, and the working layer 114. Itis believed that the present invention can provide a controllable layerthickness at an accuracy of around 500 Angstroms. It should also bementioned that the present invention may be used to form a depositionlayer with one or any multiple of sublayers.

The thickness of the deposition layer is normally determined based onthe nature of intended use of the plasma plated substrate. This mayinclude such variables as the temperature, pressure, and humidity of theoperating environment, among many other variables and factors. Theselection of the desired metal or depositant type for each layer is alsohighly dependant upon the nature of the intended use of the plasmaplated substrate.

For example, the present invention prevents or substantially reducesgalling or mating or interlocking components. Galling includes theseizure of mated components that often occur when two surfaces, such asthreaded surfaces, are loaded together. Galling can cause components tofracture and break, which often results in severe damage. Plasma platingmay be used to prevent or reduce galling by plating one or morecontacting surfaces.

Various depositants may be used to achieve this beneficial effect. It isbelieved, however, that galling is preferably reduced through a plasmaplating process that deposits a base layer of nickel or titanium and aworking layer of a silver/palladium metal alloy on one or morecontacting surfaces. For high temperature applications, such as over 650degrees Fahrenheit, it is believed that the galling is preferablyreduced through a plasma plating process that deposits a nickel ortitanium base layer and a working layer of gold.

It has been found through experimentation that chromium does not workwell to reduce galling, this includes when the chromium is deposited aseither the base layer, the transition layer, or the working layer. It isbelieved that chromium may be a depositant that is more difficult tocontrol during the plasma plating process.

Plasma plating may also be used to plate valve parts, such as valvestems in nonnuclear applications, and are preferably plasma plated usinga titanium base layer, a gold transition layer, and an indium workinglayer. In nuclear applications, such as nuclear power plantapplications, indium is not a preferred plasma plating depositantbecause it is considered to be too much of a radioactive isotopeabsorber. Instead, valve stems in nuclear applications are preferablyplasma plated using a nickel base layer and a silver/palladium metalalloy working layer.

As is illustrated in FIG. 4, the working layer 14 is normally providedat a substantially larger thickness than the corresponding transitionlayer 112 and the base layer 110. It should also be noted that thecoating of the top of the substrate 12 is shown to be thin at or nearthe center or middle of the substrate 12. This effect is due to how thefilaments are positioned during the plasma plating process. For example,if the filaments are positioned similarly to that illustrated in FIGS.2-3, the middle or center portion of the substrate 12 will generallyhave a thinner overall profile than the side of the deposition layer.

Although various ranges of thicknesses have been discussed herein, itshould be understood that the present invention is not limited to anymaximum deposition layer thickness. The thickness of the depositionlayer, especially the thickness of the working layer 114, can beprovided at virtually any desired thickness, normally depending upon theoperating environment in which the plasma plated substrate 12 will beintroduced. The base layer 110 and the transition layer 112 and anyother layers below the working layer 114 will preferably be provided ata substantially smaller thickness than the corresponding thickness ofthe working layer 114. For example, the base layer 110 and thetransition layer 112 may be provided at a thickness ranging from 500 to750 Angstroms while the working layer 114 may be provided at virtuallyany thickness such as for example 18,000 Angstroms.

FIG. 5 is a flow chart of a method 500 for plasma plating according toan embodiment of the present invention. The method 500 begins at block502 and proceeds to block 504. At block 504, the material or substratethat will be plasma plated is prepared for the process. This may includecleaning the substrate to remove any foreign materials, contaminants,and oils. Any of a variety of known cleaning processes may be used suchas those defined by the Steel Structures Painting Council (SSPC). Forexample, the SSPC-5 standard may be employed to ensure that a substrateis cleaned to a white metal condition. Similarly, the SSPC-10 standardmay be employed. Preferably, the substrate will undergo an abrasiveblasting, such as for example, bead blasting to further ensure that anyforeign materials or contaminants are removed. It should be noted thatan oxidation layer may be present on the surface of the substrate. Thepresent invention allows for a deposition layer to be plasma plated ontothe substrate surface, even in the presence of an oxidation layer, withexcellent adhesion and mechanical properties.

The method 500 proceeds next to block 506 where the plasma platingsystem prerequisites are established. Depending upon the implementationof the system for plasma plating, this may involve any of a variety ofitems. In the situation where a diffusion pump is used as part of thevacuum system, items such as the availability of cooling water must beestablished. Similarly, the adequate availability of lube oil and air tooperate the various equipment, valves, and machinery associated with thesystem for plasma plating must be established. An adequate supply ofgas, such as argon gas, should also be verified and checked at thispoint before proceeding to block 510.

At block 510, assuming that a diffusion pump is used as part of thevacuum system, the diffusion pump is prepared for operation. This mayinclude opening a foreline valve and the starting of the foreline vacuumpump which is used in combination with the diffusion pump. Once aforeline vacuum has been drawn, the heaters of the diffusion pump may beenergized. This places the diffusion pump in service.

The method 500 proceeds next to block 512 where the vacuum chamber isset up. This includes any number of processes such as positioning thesubstrate within the vacuum chamber. This is normally achieved bypositioning or placing the substrate at a specified location on aplatform or turntable located within the vacuum chamber. Beforeaccessing the internal volume of the vacuum chamber, the vacuum chamberseal must be broken and the bell jar or outer member is preferablylifted away from its base plate. Once the substrate is positioned on theplatform, the filaments may be positioned relative to the placement ofthe substrate.

The positioning of the filaments may involve any number of techniquesand includes such variables as the amount and type of depositant to beprovided at the filament, and the distance, not only relative to thesubstrate, but relative to other filaments. Generally, the filament willbe located a distance ranging from 0.1 inches to 6 inches from thesubstrate, as measured from the center line of the filament, or from thedepositant, to the closest point of the substrate. Preferably, however,the distance between the filament or the depositant and the substratewill range anywhere from 2.75 inches to 3.25 inches when the depositantwill serve as the base layer or transition layer of the depositionlayer. Similarly, when the depositant will serve as the working layer ofthe deposition layer that will be deposited on the substrate, thedistance between the filament or the depositant and the substrate ispreferably provided at a distance between 2 inches and 2.5 inches.

In the situation where multiple depositants or multiple shots will beperformed in the plasma plating process, it is necessary to consider theplacement of the filaments that will hold the first depositant relativeto those that will hold the second depositant as well as each of thefilament's position relative to each other and the substrate. Generallythe distance of a second filament from a first filament, which willinclude a depositant that will serve as a base layer, transition layer,or a working layer of a deposition layer, should be anywhere between 0.1inches and 6 inches.

The spacing between filaments that include depositants that will serveas a base layer, is generally provided between 0.1 inches and 6 inches.Preferably, this distance shall be between 3 inches and 4 inches. Theforegoing filament spacing information also applies when the depositantprovided in the filaments will serve as the transition layer in thedeposition layer. Similarly, the spacing between filaments, whichinclude a depositant that will serve as the working layer of thedeposition layer, should generally be between 0.1 inches and 6 inches,but, preferably, will be between 2.5 inches and 3 inches.

The chamber setup of block 512 may also need to take into account thearrangement of an array of substrates on the platform that are beingplasma plated. For example, a filament that is positioned in the vacuumchamber so that it will provide a dispersion pattern to providedepositant coverage to inwardly facing surfaces of an array ofsubstrates, it may require anywhere from 20 to 80 percent less mass orweight of depositant when compared with a filament positioned in thevacuum chamber to provide coverage for the array of outwardly facingsurfaces. The reference to inwardly and outwardly are relative to theplatform or turntable with inwardly referring to those surfaces closerto the center of the platform or turntable. This is because theefficiency of the plasma plating process is greater for the inwardlyfacing surfaces of an array of substrates than at the outwardly facingsurfaces of the array of substrates because of the forces attractingthe, generally, positive ions of the plasma. This also ensures that thethickness of the deposition layer on the inwardly facing surfaces andthe outwardly facing surfaces are more uniform. In such a case, theweight or mass of the depositant will, preferably, need to vary betweensuch filament positions. Generally, the variance in mass or weightbetween the two locations may be anywhere from 20 to 80 percentdifferent. Preferably, the depositants in the filaments covering theinwardly facing surfaces will use 40 to 50 percent less mass or weightthan the depositants of the filaments covering the outwardly facingsurfaces. The amount of the depositant placed in the filamentscorresponds to the desired thickness of the deposition layer, and anysublayers thereof. This was discussed more fully and is illustrated morefully in connection with FIG. 3.

The type of filament affects the dispersion pattern achieved through themelting or evaporation of its depositant during the creation of theplasma. Any of a variety of filament types, shapes, and configurationsmay be used in the present invention. For example, the filament may beprovided as a tungsten basket, a boat, a coil, a crucible, a ray gun, anelectron beam gun, a heat gun, or as any other structure, such as asupport structure provided within the vacuum chamber. The filaments aregenerally heated through the application of an electric current throughthe filament. However, any method or means of heating the depositantwithin the filament may be used in the present invention.

The setup of the vacuum chamber also includes placing the depositants inthe one or more filaments. The present invention contemplates the use ofvirtually any material that is capable of being evaporated under theconditions and parameters of the present invention so that a plasma willform. For example, the depositant may include virtually any metal, suchas a metal alloy, gold, titanium, chromium, nickel, silver, tin, indium,lead, copper, palladium, silver/palladium and any of a variety ofothers. Similarly, the depositant may include any other materials suchas carbon, nonmetals, ceramics, metal carbides, metal nitrates, and anyof a variety of other materials. The depositants will generally beprovided in a pellet, granule, particle, powder, wire, ribbon, or stripform. Once the filaments have been properly positioned and loaded, thevacuum chamber may be closed and sealed. This may include sealing thebell portion of the vacuum chamber with its base plate.

The method 500 proceeds next to block 514 where preparations are made tobegin establishing a vacuum condition within the vacuum chamber. In oneembodiment, such as the system 10 shown in FIG. 1, a roughing pump isstarted to begin evacuating the vacuum chamber and to bring the pressuredown within the vacuum chamber to a sufficient level so that additionalpumps may take over to further reduce the pressure within the vacuumchamber. In one embodiment, the roughing vacuum pump is a mechanicalpump that may be started, and a roughing valve may then be opened toprovide access to the vacuum chamber. Once the roughing vacuum pump hasachieved its desired function and has reduced the pressure in the vacuumchamber to its desired or designed level, the roughing valve is shut. Atthis point, the method 500 transitions to block 516.

At block 516, the pressure within the vacuum chamber is further reducedusing another vacuum pump. For example, in one embodiment, a diffusionpump/foreline pump is utilized to further reduce the pressure within thevacuum chamber. In the embodiment of the present invention asillustrated in FIG. 1, this is achieved by opening the main valve andallowing the diffusion pump, supported by the mechanical foreline pump,to further pull or reduce the pressure in the vacuum chamber.

Generally, the pressure in the vacuum chamber is reduced to a level thatis at or below 4 milliTorr. Preferably, the pressure in the vacuumchamber is reduced to a level that is at or below 1.5 milliTorr. In theevent that backsputtering, which is described below in connection withblock 518 of the method 500, is to be performed, the pressure in thevacuum chamber is reduced to a level below 100 milliTorr and generallyin a range between 20 milliTorr and 100 milliTorr. In a preferredembodiment when backsputtering is to be performed, the pressure isreduced in the vacuum chamber at a level below 50 milliTorr, andgenerally at a level between 20 milliTorr and 50 milliTorr.

Preceding next to block 518, a backsputtering process may be performedto further clean and prepare the substrate. It should be understood,however, that such a process is not mandatory. The backsputteringprocess is described in more detail below in connection with FIG. 6. Thebacksputtering process may include the rotation of the platform orturntable within the vacuum chamber. In such a case, the turntable willgenerally be rotated at a rate at or between 5 revolutions per minuteand 30 revolutions per minute. Preferably, the turntable will be rotatedat a rate between 12 revolutions per minute and 15 revolutions perminute. The operation of the turntable, which also will preferably beused as the deposition layer is being formed on the substrate accordingto the teachings of the present invention.

Method 500 proceeds next to block 520 where an operating vacuum isestablished. Although a vacuum condition has already been establishedwithin the vacuum chamber, as previously discussed in connection withblock 514 and 516, an operating vacuum can now be established throughthe introduction of a gas into the vacuum chamber at a flow rate thatwill raise the pressure in the vacuum chamber to a level generally at orbetween 0.1 milliTorr and 4 milliTorr. Preferably, the introduction ofthe gas is used to raise the pressure in the vacuum chamber to a levelthat is at or between 0.5 milliTorr and 1.5 milliTorr. This will ensurethat there are no depositant ion collisions within the plasma, whichwill increase the depositant efficiency and provide a clean, highlyadhered deposition layer to the substrate. The gas that is introducedinto the vacuum chamber may be any of a variety of gases but willpreferably be provided as an inert gas, a noble gas, a reactive gas or agas such as argon, xenon, radon, helium, neon, krypton, oxygen,nitrogen, and a variety of other gases. It is desirable that the gas isa noncombustible gas. It should be understood that the present inventiondoes not require the introduction of a gas but may be performed in theabsence of a gas.

At block 522, various operating parameters and values of the system areestablished. This will generally include the rotation of a turntable, ifdesired, the application of a dc signal, and the application of a radiofrequency signal. Assuming that the platform includes a turntable orsome other rotating device, the turntable rotation will preferably beestablished at this point. This assumes, of course, that the rotation ofthe turntable was not previously started and the discretionarybacksputtering block 518. Once the rotation of the turntable has beenestablished, the dc signal and the rf signal may be applied to thesubstrate. The application of the dc signal to the substrate willgenerally be provided at a voltage amplitude that is at or between onevolt and 5,000 volts. Note that the polarity of the voltage willpreferably be negative; however, this is not always required. In apreferred embodiment, the application of the dc signal to the substratewill be provided at a voltage level at or between negative 500 volts andnegative 750 volts.

The application of the radio frequency signal to the substrate willgenerally be provided at a power level that is at or between 1 watt and50 watts. Preferably, the power level of the radio frequency signal willbe provided at 10 watts or between a range defined by 5 watts and 15watts. The frequency of the radio frequency signal will generally beprovided at an industrial specified frequency value in either thekilohertz range or the megahertz range. Preferably, the frequency signalwill be provided at a frequency of 13.56 kilohertz. Although the termradio frequency has been used throughout to describe the generation andapplication of the radio frequency signal to the substrate, it should beunderstood that the term radio frequency should not be limited to itscommonly understood definition of signals having frequencies roughlybetween 10 kilohertz and 100,000 megahertz. The term radio frequencyshall also include any signal with a frequency component that isoperable or capable of assisting with the creation or excitation of aplasma in a vacuum chamber.

Block 522 will also preferably include the mixing of the dc signal andthe radio frequency signal, using mixer circuitry, to generate a mixedsignal. This allows only one signal to be applied to the substrate. Thisis generally achieved using the electrical feed through that extendsthrough the base plate of the vacuum chamber and contacts anelectrically conductive portion of the platform, which in turnelectrically couples to the substrate or substrates. Block 522 may alsoinclude the balancing of the mixed signal through the use of a radiofrequency balancing network. Preferably, the mixed signal is balanced byminimizing the standing wave reflected power. This is preferablycontrolled through a manual control.

As the output or load characteristics of the antenna or output changes,as seen from the mixer circuitry, problems can arise when electricalsignals or waves are reflected from the output load back to the mixer orsource. These problems may include damage to the radio frequencytransmitter and a reduction in the transfer of power to the substrateand vacuum chamber to ensure the formation of a sufficient plasma toachieve a successful plasma plating process.

This problem can be reduced or solved by including the radio frequencybalancing network that can adjust its impedance, including in oneembodiment its resistance, inductance, and capacitance, to match orreduce the presence of reflected waves. The impedance and electricalcharacteristics of the output load or antenna are affected by suchthings as the presence and/or absence of a plasma and the shape andproperties of the substrate or substrates on the platform. Because ofsuch changes during the plasma plating process, the radio frequencybalancing network may need to be adjusted during the process to minimizethe standing wave reflected power or, stated differently, to prevent orreduce the standing wave ratio return to the radio frequencytransmitter. Preferably, these adjustments are performed manually by anoperator during the plasma plating process. In other embodiments, theradio frequency balancing network is automatically adjusted. Care mustbe taken, however, to ensure that the automatic adjustment does not overcompensate or poorly track the changes in the output load.

The method 500 proceeds next to block 524 where the depositant ordepositants are melted or evaporated so that a plasma will be generated.The generation of the plasma at the conditions provided by the presentinvention will result in a deposition layer being formed on the surfaceof the substrate through plasma plating. It is believed that thedeposition layer is formed at a medium energy level on the average ofbetween 10 eV and 90 eV.

The depositants are generally evaporated or vaporized by providing acurrent through the filament around the depositant. In a preferredembodiment, the depositants are slowly or incrementally heated toachieve a more even heat distribution in the depositant. This alsoimproves the formation of the plasma. The current may be provided as analternating current or as any other current that is sufficient togenerate heat in the filament that will melt the depositant. In otherembodiments, the depositant may be heated through the introduction of anagent that is in chemical contact with the depositant. In still otherembodiments, the depositant may be heated through the use ofelectromagnetic or microwave energy.

The conditions in the vacuum chamber will be correct for the formationof a plasma. The plasma will generally include gas ions, such as argonions, and depositant ions, such as gold, nickel, or palladium ions. Thegas ions and the depositant ions will generally be provided as positiveions due to the absence of one or more electrons. The creation of theplasma is believed to be assisted through the introduction of the radiofrequency signal and because of thermionic phenomena due to the heatingof the depositants. It is contemplated that in some situations, a plasmamay be generated that includes negatively charged ions.

The negative potential established at the substrate due to the dc signalwill attract the positive ions of the plasma. Once again, this willprimarily include depositant ions and may include gas ions, such asargon gas ions from the gas that was introduced earlier in method 500.The inclusion of the gas ions, such as argon ions, are not believed todegrade the material or mechanical characteristics of the depositionlayer.

It should be noted that some prior literature has suggested that theintroduction of a magnet at or near the substrate is desirable toinfluence the path of the ions of the plasma as they are attracted tothe substrate to form the deposition layer. Experimental evidence nowsuggests that the introduction of such a magnet is actually undesirableand produced unwanted effects. The presence of the magnet may lead touneven deposition thicknesses, and prevent or significantly impede thecontrollability, repeatability, and reliability of the process.

Whenever the deposition layer is designed to include multiple sublayers,multiple shots must be performed at block 524. This means that once thebase layer depositants have been melted through the heating of theirfilaments, the transition layer depositants (or the depositant of thenext layer to be applied) are heated and melted by the introduction ofheat at their filaments. In this manner, any number of sublayers may beadded to the deposition layer. Before successive depositant sublayersare formed, the preceding layer shall have been fully or almost fullyformed. The method 500 thus provides the significant advantage ofallowing a deposition layer to be created through multiple sublayerswithout having to break vacuum and reestablish vacuum in the vacuumchamber. This can significantly cut overall plasma plating time andcosts.

The method 500 proceeds next to block 526 where the process or system isshut down. In the embodiment of the system shown in FIG. 1, the mainvalve is closed and a vent valve to the vacuum chamber is opened toequalize pressure inside the vacuum chamber. The vacuum chamber may thenbe opened and the substrate items may be immediately removed. This isbecause the method 500 does not generate excessive heat in thesubstrates during the plasma plating process. This provides significantadvantages because the material or mechanical structure of the substrateand deposition layer are not adversely affected by excessivetemperature. The plasma plated substrates may then be used as needed.Because the temperature of the substrates are generally at a temperatureat or below 125 Fahrenheit, the substrates can generally be immediatelyhandled without any thermal protection.

The method 500 provides the additional benefit of not generating anywaste byproducts and is environmentally safe. Further, the method 500 isan efficient process that efficiently uses the depositants such thatexpensive or precious metals, such as gold and silver, are efficientlyutilized and are not wasted. Further, due to the fact that the presentinvention does not use high energy deposition techniques, no adversemetallurgical or mechanical effects are done to the substrate. This isbelieved to be due to the fact that the deposition layer of the presentinvention is not deeply embedded within the substrate, but excellentadherence, mechanical, and material properties are still exhibited bythe deposition layer. After the substrates have been removed at block528, the method 500 ends at block 530.

FIG. 6 is a flow chart of a method 600 for backsputtering using thesystem and method of the present invention, according to an embodimentof the present invention. As mentioned previously, backsputtering may beused to further clean the substrate before a deposition layer is formedon the substrate through plasma plating. Backsputtering generallyremoves contaminants and foreign materials. This results in a cleanersubstrate which results in a stronger and more uniform deposition layer.The method 600 begins at block 602 and proceeds to block 604 where a gasis introduced into the vacuum chamber at a rate that maintains orproduces a desired pressure within the vacuum chamber. This is similarto what was previously described in block 520 in connection with FIG. 5.Generally, the pressure in the vacuum chamber should be at a level at orbelow 100 milliTorr, such as at a range between 20 milliTorr and 100milliTorr. Preferably, the pressure is provided at a level at or between30 milliTorr and 50 milliTorr.

The method 600 proceeds next to block 606 where rotation of the platformor turntable is established, if applicable. As mentioned previously, therotation of the turntable may be provided at a rate between 5revolutions per minute and 30 revolutions per minute but is preferablyprovided at a rate between 12 revolutions per minute and 15 revolutionsper minute.

Proceeding next to block 608, a dc signal is established and is appliedto the substrate. The dc signal will generally be provided at anamplitude at or between one volt and 4,000 volts. Preferably, the dcsignal will be provided at a voltage between negative 100 volts andnegative 250 volts.

Block 608 also involves the generation of a radio frequency signal thatwill be applied to the substrate. The radio frequency signal willgenerally be provided at a power level at or between 1 watt and 50watts. Preferably, the radio frequency signal will be provided at apower level of 10 watts or at or between 5 and 15 watts. The dc signaland the radio frequency signal are preferably mixed, balanced, andapplied to the substrate as a mixed signal. As a consequence, a plasmawill form from the gas that was introduced at block 604. This gas willgenerally be an inert gas or noble gas such as argon. The formation ofthe plasma includes positive ions from the gas. These positive ions ofthe plasma will be attracted and accelerated to the substrate, whichwill preferably be provided at a negative potential. This results incontaminants being scrubbed or removed from the substrate. Once thecontaminants or foreign matter are removed from the substrate, they aresucked out of the vacuum chamber through the operation of the vacuumpump, such as the diffusion pump.

Proceeding next to block 610, the backsputtering process continues for aperiod of time that is generally between 30 seconds and one minute.Depending on the condition and cleanliness of the substrate, thebacksputtering process may continue for more or less time. Generally,the backsputtering process is allowed to continue until the capacitancedischarge, created by the backsputtering process is substantiallycomplete or is significantly reduced. This may be visually monitoredthrough the observation of sparks or light bursts that coincide with thecapacitive discharge from the contaminants from the substrate. This maybe referred to as microarcing.

During the backsputtering process, the dc signal must be controlled.This is normally achieved through manual adjustments of a dc powersupply. Preferably, the voltage of the dc signal is provided at a levelthat allows the voltage to be maximized without overloading the dc powersupply. As the backsputtering process continues, the current in the dcpower supply will vary because of changes in the plasma that occurduring the backsputtering process. This makes it necessary to adjust thevoltage level of the dc signal during the backsputtering process.

The method 600 proceeds next to block 612 where the dc signal and theradio frequency signal are removed and the gas is shut off. The method600 proceeds next to block 614 where the method ends.

Thus, it is apparent that there has been provided, in accordance withthe present invention, a system and method for plasma plating thatsatisfies one or more of the advantages set forth above. Although thepreferred embodiment has been described in detail, it should beunderstood that various changes, substitutions, and alterations can bemade herein without departing from the scope of the present invention,even if all, one, or some of the advantages identified above are notpresent. For example, the dc signal and the radio frequency signal maybe electrically coupled to the substrate using virtually any availableelectrically conductive path. The present invention may be implementedusing any of a variety of materials and configurations. For example, anyof a variety of vacuum pump systems, equipment, and technology could beused in the present invention. The present invention also does notrequire the presence of a gas, such as argon, to form a plasma, and thebacksputtering process is not a mandatory process to practice thepresent invention. These are only a few of the examples of otherarrangements or configurations of the system and method that iscontemplated and covered by the present invention.

The various components, equipment, substances, elements, and processesdescribed and illustrated in the preferred embodiment as discrete orseparate may be combined or integrated with other elements and processeswithout departing from the scope of the present invention. The presentinvention may be used to plasma plate virtually any material, object, orsubstrate using any of a variety of depositants. Other examples ofchanges, substitutions, and alterations are readily ascertainable by oneskilled in the art and could be made without departing from the spiritand scope of the present invention.

1. A method for plasma plating comprising: positioning a substrate witha threaded surface on a platform within a vacuum chamber, wherein aninwardly facing surface of the substrate faces a center of the platformand an outwardly facing surface of the substrate faces an edge of theplatform and wherein the platform further comprises a turntable operableto rotate the substrate; positioning a first depositant in a firstevaporation source within the vacuum chamber, the first depositantincludes at least a first metal; positioning a second depositant in asecond evaporation source within the vacuum chamber, wherein the firstevaporation source and second evaporation source are arranged so thatrotation of the turntable moves the inwardly facing surface of thesubstrate past the first evaporation source at a first time and theoutwardly facing surface of the substrate past the second evaporationsource at a second time; reducing an initial pressure in the vacuumchamber to at or below 4 milliTorr; flowing a gas through the vacuumchamber at a rate to raise the pressure in the vacuum chamber to at orbetween 0.1 milliTorr and 4 milliTorr; applying a negative dc signal tothe substrate at a voltage amplitude at or between one to 1,500;applying a radio frequency signal to the substrate at a power level ator between 1 watt and 50 watts; and heating the first depositant and thesecond depositant to temperatures at or above the respective meltingpoints of the depositants, whereby a plasma is generated in the vacuumchamber, the plasma includes a mixture of positively charged depositantions and negatively charged electrons, and the depositant ions areplated on the threaded surface of the substrate to create a platedthreaded surface, wherein the inwardly facing surface and the outwardlyfacing surface of the substrate encompasses the plated threaded surface,and wherein the plated threaded surface reduces galling between theplated threaded surface and a surface of a mated component.
 2. Themethod of claim 1, wherein the initial pressure is reduced in the vacuumchamber to at or below 1.5 milliTorr, and wherein gas is flowed throughthe vacuum chamber at a rate to raise the pressure in the vacuum chamberto at or between 0.5 milliTorr and 1.5 milliTorr.
 3. The method of claim1, wherein the negative dc signal is applied to the substrate at avoltage amplitude at or between negative 500 volts and negative 750volts.
 4. The method of claim 1, wherein the power level is provided ator between 5 watts and 15 watts.
 5. The method of claim 1, wherein thepower level is around 10 watts.
 6. The method of claim 1, wherein theinitial pressure is reduced in the vacuum chamber to at or below 1.5milliTorr, and the gas is flowed through the vacuum chamber at a rate toraise the pressure in the vacuum chamber to at or between 0.5 milliTorrand 1.5 milliTorr, wherein a negative dc signal is applied to thesubstrate at a voltage amplitude at or between negative 500 volts andnegative 750 volts, and wherein the power level is provided at orbetween 5 and 15 watts.
 7. The method of claim 1, further comprising:rotating the turntable at a revolutions per minute rate at or between 5revolutions per minute and 30 revolutions per minute.
 8. The method ofclaim 1, further comprising: rotating the turntable at a rotational rateof revolutions per minute at or between 12 revolutions per minute and 15revolutions per minute.
 9. The method of claim 1, wherein the turntableincludes an electrically conductive material that provides anelectrically conductive path to the substrate, and applying the dcsignal to the substrate and applying the radio frequency signal to thesubstrate include applying the dc signal and the radio frequency signalto the electrically conductive material of the turntable.
 10. The methodof claim 9, wherein the dc signal and the radio frequency signal areapplied to the electrically conductive material of the turntable using acommutator.
 11. The method of claim 9, wherein the dc signal and theradio frequency signal are applied to the electrically conductivematerial of the turntable using an electrically conductive brush. 12.The method of claim 1, wherein the platform is included as part of thevacuum chamber.
 13. The method of claim 1, wherein the platform is aflat surface.
 14. The method of claim 1, wherein the platform includes ahorizontal surface.
 15. The method of claim 1, wherein the platformincludes an electrically conductive material.
 16. The method of claim 1,wherein the platform is a conductive plate.
 17. The method of claim 1,further comprising: mixing the dc signal and the radio frequency signalto generate a mixed signal, and wherein the dc signal and the radiofrequency signal includes applying the mixed signal to the substrate.18. The method of claim 17, wherein the mixing the dc signal and theradio frequency signal includes mixing a negative dc signal and theradio frequency signal.
 19. The method of claim 17, further comprising:balancing the mixed signal by minimizing the standing wave reflectedpower.
 20. The method of claim 19, wherein minimizing the standing wavereflected power is achieved using a manual control.
 21. The method ofclaim 19, wherein minimizing the standing wave reflected power isachieved using an automatic control.
 22. The method of claim 1, furthercomprising: positioning at least one of the first evaporation source andthe second evaporation source relative to the substrate.
 23. The methodof claim 22, wherein positioning the at least one of the firstevaporation source and the second evaporation source includespositioning the at least one of the first evaporation source and thesecond evaporation source a distance from the substrate.
 24. The methodof claim 23, wherein the distance is at or between 0.1 inches and 6inches when at least one of the first depositant and the seconddepositant in the respective at least one of the first evaporationsource and the second evaporation source is to be deposited as a baselayer.
 25. The method of claim 24, wherein the distance is at or between2.75 inches and 3.25 inches when at least one of the first depositantand the second depositant in the respective at least one of the firstevaporation source and the second evaporation source is to be depositedas the base layer.
 26. The method of claim 23, wherein the distance isat or between 0.1 inches and 6 inches when at least one of the firstdepositant and the second depositant in the respective at least one ofthe first evaporation source and the second evaporation source is to bedeposited as a transition layer.
 27. The method of claim 26, wherein thedistance is at or between 2.75 inches and 3.25 inches when at least oneof the first depositant and the second depositant in the respective atleast one of the first evaporation source and the second evaporationsource is to be deposited as the transition layer.
 28. The method ofclaim 23, wherein the distance is at or between 0.1 inches and 6 incheswhen at least one of the first depositant and the second depositant inthe respective at least one of the first evaporation source and thesecond evaporation source is to be deposited as a working layer.
 29. Themethod of claim 28, wherein the distance is at or between 2.0 inches and2.5 inches when at least one of the first depositant and the seconddepositant in the respective at least one of the first evaporationsource and the second evaporation source is to be deposited as theworking layer.
 30. The method of 1, further comprising positioning thefirst evaporation source a distance from the second evaporation source.31. The method of claim 30, wherein the distance is at or between 0.1inches and 6 inches when at least one of the first depositant and thesecond depositant in the respective at least one of the firstevaporation source and the second evaporation source is to be depositedas a base layer.
 32. The method of claim 31, wherein the distance is ator between 3.0 inches and 4.0 inches when at least one of the firstdepositant and the second depositant in the respective at least one ofthe first evaporation source and the second evaporation source is to bedeposited as the base layer.
 33. The method of claim 30, wherein thedistance is at or between 0.1 inches and 6 inches when at least one ofthe first depositant and the second depositant in the respective atleast one of the first evaporation source and the second evaporationsource is to be deposited as a transition layer.
 34. The method of claim33, wherein the distance is at or between 3.0 inches and 4.0 inches whenat least one of the first depositant and the second depositant in therespective at least one of the first evaporation source and the secondevaporation source is to be deposited as the transition layer.
 35. Themethod of claim 30, wherein the distance is at or between 0.1 inches and6 inches when at least one of the first depositant and the seconddepositant in the respective at least one of the first evaporationsource and the second evaporation source is to be deposited as a workinglayer.
 36. The method of claim 35, wherein the distance is at or between2.5 inches and 3.0 inches when at least one of the first depositant andthe second depositant in the respective at least one of the firstevaporation source and the second evaporation source is to be depositedas the working layer.
 37. The method of claim 1, further comprising: anarray of substrates, and the substrate is provided as one of the arrayof substrates; positioning the first evaporation source relative toinwardly facing surfaces of the array of substrates; and positioning thesecond evaporation source relative to outwardly facing surfaces of thearray of substrates.
 38. The method of 37, wherein the total mass of thesecond depositant is 20 to 80 percent less than the total mass of thedepositant.
 39. The method of 38, wherein the total mass of the seconddepositant is 40 to 50 percent less than the total mass of thedepositant.
 40. The method of claim 1, further comprising: positioningthe second depositant in the second evaporation source within the vacuumchamber before reducing the initial pressure in the vacuum chamber to ator below 4 milliTorr; and heating the second depositant to at or abovethe melting point of the second depositant, whereby a second plasma isgenerated in the vacuum chamber, the second plasma includes a mixture ofpositively charged second depositant ions and negatively chargedelectrons, and the second depositant ions are plated on the threadedsurface of the substrate.
 41. The method of claim 40, wherein the firstdepositant forms a base layer on the substrate and the second depositantforms a working layer on the base layer.
 42. The method of claim 40,further comprising: positioning a third depositant in a thirdevaporation source within the vacuum chamber before reducing the initialpressure in the vacuum chamber to at or below 4 milliTorr; and heatingthe third depositant to a temperature at or above the melting point ofthe third depositant, whereby a third plasma is generated in the vacuumchamber, the third plasma includes a mixture of positively charged thirddepositant ions and negatively charged electrons, and the thirddepositant ions are plated on the substrate.
 43. The method of claim 42,wherein the first depositant forms a base layer on the substrate, thesecond depositant forms a transition layer on the base layer, and thethird depositant forms a working layer on the transition layer.
 44. Themethod of claim 1, wherein the radio frequency signal is provided at afrequency above one kilohertz range.
 45. The method of claim 1, whereinthe radio frequency signal is provided at a frequency above onemegahertz range.
 46. The method of claim 1, wherein the radio frequencysignal is provided at a frequency of 13.56 kilohertz.
 47. The method ofclaim 1, wherein the radio frequency signal is provided at a frequencyreserved for industrial applications.
 48. The method of claim 1, furthercomprising: cleaning the substrate to remove foreign materials and oils.49. The method of claim 1, further comprising: cleaning the substrate toachieve white metal clean.
 50. The method of claim 1, furthercomprising: cleaning the substrate before positioning the substratewithin the vacuum chamber.
 51. The method of claim 50, wherein thecleaning the substrate includes abrasively blasting the substrate. 52.The method of claim 1, wherein the gas is introduced through a controlvalve.
 53. The method of claim 1, wherein at least one of the firstdepositant and the second depositant is a metal alloy.
 54. The method ofclaim 1, wherein at least one of the first depositant and the seconddepositant is gold.
 55. The method of claim 1, wherein at least one ofthe first depositant and the second depositant is titanium.
 56. Themethod of claim 1, wherein at least one of the first depositant and thesecond depositant is chromium.
 57. The method of claim 1, wherein atleast one of the first depositant and the second depositant is nickel.58. The method of claim 1, wherein at least one of the first depositantand the second depositant is silver.
 59. The method of claim 1, whereinat least one of the first depositant and the second depositant is tin.60. The method of claim 1, wherein at least one of the first depositantand the second depositant is indium.
 61. The method of claim 1, whereinat least one of the first depositant and the second depositant is lead.62. The method of claim 1, wherein at least one of the first depositantand the second depositant is copper.
 63. The method of claim 1, whereinat least one of the first depositant and the second depositant ispalladium.
 64. The method of claim 1, wherein at least one of the firstdepositant and the second depositant is a silver/palladium metal alloy.65. The method of claim 1, wherein at least one of the first depositantand the second depositant is carbon.
 66. The method of claim 1, whereinat least one of the first depositant and the second depositant is ametal carbide.
 67. The method of claim 1, wherein at least one of thefirst depositant and the second depositant is a metal nitride.
 68. Themethod of claim 1, wherein at least one of the first depositant and thesecond depositant is provided in a form from the class consisting of apellet, a wire, a granule, a powder, a ribbon, and a strip.
 69. Themethod of claim 1, wherein the gas is an inert gas.
 70. The method ofclaim 1, wherein the gas is argon.
 71. The method of claim 1, whereinthe gas is xenon.
 72. The method of claim 1, wherein the gas is radon.73. The method of claim 1, wherein the gas is helium.
 74. The method ofclaim 1, wherein the gas is neon.
 75. The method of claim 1, wherein thegas is krypton.
 76. The method of claim 1, wherein the gas is oxygen.77. The method of claim 1, wherein the gas is nitrogen.
 78. The methodof claim 1, wherein the gas is noncombustible.
 79. The method of claim1, wherein the plasma includes gas ions and depositant ions.
 80. Themethod of claim 74, wherein the gas ions and the depositant ions of theplasma include positively charged ions.
 81. The method of claim 74,wherein the gas ions and the depositant ions of the plasma includenegatively charged ions.
 82. The method of claim 1, wherein the gas isargon and at least one of the first depositant and the second depositantis a metal alloy of silver/palladium, and the plasma includes argon ionsand silver/palladium ions.
 83. The method of claim 1, wherein at leastone of the first evaporation source and the second evaporation source isa tungsten basket.
 84. The method of claim 1, wherein at least one ofthe first evaporation source and the second evaporation source is acoil.
 85. The method of claim 1, wherein heating the first depositantand the second depositant includes supplying a current through the firstevaporation source and the second evaporation source.
 86. The method ofclaim 85, wherein heating the first depositant and the second depositantincludes incremental staging of the current to the first evaporationsource and the second evaporation source to achieve an even heatdistribution in the first depositant and the second depositant.
 87. Themethod of claim 85, wherein the current is an alternating current. 88.The method of claim 87, wherein the amplitude of the alternating currentis controllably increased such that the at least one of the firstdepositant and the second depositant is uniformly heated and melted. 89.The method of claim 1, wherein the method does not include the additionof a magnet to produce a magnetic field near the substrate that affectsthe attraction of the ions of the plasma to the substrate.
 90. Themethod of claim 1, wherein the plasma forms a layer on the substrate tocreate the plated threaded surface at a thickness at or between 500 and20,000 Angstroms.
 91. The method of claim 1, wherein the plasma forms alayer on the substrate to create the plated threaded surface at athickness at or between 3,000 and 10,000 Angstroms.
 92. The method ofclaim 1, wherein the plasma forms a layer on the substrate to create theplated threaded surface that can be controlled to a thickness of 500Angstroms.
 93. The method of claim 1, further comprising: backsputteringthe substrate before heating at least one of the first depositant andthe second depositant to a temperature at or above the melting point ofthe at least one of the first depositant and the second depositant. 94.The method of claim 1, further comprising: performing backsputteringbefore heating the first depositant and the second depositant thatincludes: reducing the pressure in the vacuum chamber to at or below 100milliTorr; flowing a gas through the vacuum chamber at a rate to raisethe pressure in the vacuum chamber to at or between 20 milliTorr and 100milliTorr; applying a dc signal to the substrate at a voltage amplitudeat or between 1 volt and 4000 volts; and applying a radio frequencysignal to the substrate at a power level at or between 1 watt and 50watts.
 95. The method of claim 94, wherein reducing the pressure in thevacuum chamber includes reducing the pressure in the vacuum chamber toat or below 50 milliTorr, and wherein flowing the gas through the vacuumchamber at a rate to raise the pressure in the vacuum chamber to at orbetween 20 milliTorr and 100 milliTorr includes flowing the gas throughthe vacuum chamber at a rate to raise the pressure to at or between 20milliTorr and 50 milliTorr.
 96. The method of claim 94, wherein applyingthe dc signal to the substrate at a voltage amplitude at or between 1volt and 4000 volts includes applying a dc signal to the substrate at avoltage amplitude at or between 100 volts and 250 volts.
 97. The methodof claim 94, wherein applying the radio frequency signal to thesubstrate at a power level at or between 1 watt and 50 watts includesapplying the radio frequency signal at a power level at or between 5 and15 watts.
 98. The method of claim 94, wherein applying the dc signal tothe substrate includes applying the dc voltage at a negative polarity.99. The method of claim 94, wherein backsputtering is performed for aperiod of time at or between 30 seconds and one minute.
 100. The methodof claim 94, wherein backsputtering is performed until the rate ofvisible microarcing is significantly reduced.
 101. A method for plasmaplating comprising: positioning a substrate with a threaded surface on aplatform within a vacuum chamber, wherein an inwardly facing surface ofthe substrate faces a center of the platform and an outwardly facingsurface of the substrate faces an edge of the platform and wherein theplatform further comprises a turntable operable to rotate the substrate;positioning a first depositant in the vacuum chamber; positioning asecond depositant in the vacuum chamber, wherein the first depositantand the second depositant are arranged so that rotation of the turntablemoves the inwardly facing surface of the substrate past the firstdepositant at a first time and the outwardly facing surface of thesubstrate past the second depositant at a second time; reducing aninitial pressure in the vacuum chamber to at or between 0.5 milliTorrand 1.5 milliTorr; applying a negative dc signal to the substrate at avoltage amplitude at or between 500 volts and 750 volts; applying aradio frequency signal to the substrate at a power level at or between 1watt and 50 watts; and heating the first depositant and the seconddepositant to temperatures at or above the respective melting points ofthe depositants, whereby a plasma is generated in the vacuum chamber,the plasma includes a mixture of positively charged depositant ions andnegatively charged electrons, and the depositant ions are plated on thethreaded surface of the substrate to create a plated threaded surface,wherein the inwardly facing surface and the outwardly facing surface ofthe substrate encompasses the plated threaded surface, and wherein theplated threaded surface reduces galling between the plated threadedsurface and a surface of a mated component.
 102. The method of claim101, wherein the power level is provided.
 103. A method for plasmaplating comprising: positioning a substrate with a threaded surface on aplatform within a vacuum chamber, wherein an inwardly facing surface ofthe substrate faces a center of the platform and an outwardly facingsurface of the substrate faces an edge of the platform and wherein theplatform further comprises a turntable operable to rotate the substrate;positioning a first depositant in a first set of filaments within thevacuum chamber, the depositant includes at least a first metal;positioning a second depositant in a second set of filaments within thevacuum chamber, wherein the first set and second set of filaments arearranged so that rotation of the turntable moves the inwardly facingsurface of the substrate past the first set of filaments at a first timeand the outwardly facing surface of the substrate past the second set offilaments at a second time; reducing an initial pressure in the vacuumchamber to at or below 4 milliTorr; flowing a gas through the vacuumchamber at a rate to raise the pressure in the vacuum chamber to at orbetween 0.1 milliTorr and 4 milliTorr; applying a negative dc signal tothe substrate at a voltage amplitude at or between one to 1,500 volts;applying a radio frequency signal to the substrate at a power level ator between 1 watt and 50 watts; and heating the first depositant and thesecond depositant to temperatures at or above their respective meltingpoints, whereby a plasma is generated in the vacuum chamber, the plasmaincludes a mixture of positively charged first and second depositantions and negatively charged electrons, and the first and seconddepositant ions are plated on the threaded surface, the inwardly facingsurface and the outwardly facing surface of the substrate to createplated surfaces, and wherein the plated surfaces reduce galling betweenthe plated surfaces and mating surfaces of a mated component.